Before doing any more with these diodes you need to read for a least a week, probably more. Look up and research these words:
IR and Near IR radiation
Eye wear for 808nm
Viewing IR with a CCD camera
Laser diode packages
Aixiz, (or other), modules
Heat sinks
Driver (DDL, RCKSTR, FlexDrive, GrooveDrive, MicroBoost, etc)
Collimating
Why not to just use AA batteries!
Not all these searches will give you the information you need by just typing them in. You may need to modify your search. Without this knowledge and understanding you are certainly going to be without any working diodes in a very short time; you may have already damaged your own eyesight, (if you have been seeing red light, that is NIR! 808nm appears as a dim, dark red dot. Try viewing it through your camera phone. You will see just how bright that light really is!); and risk damaging others eyesight if you continue.
This message may seem harsh and in a way, it's meant to. These are not toys and 300mW of IR is a really dumb idea for your first laser diode. Before purchasing you should have read
first, but now you have them, listen to the wisdom of everyone here and leave them alone until you know, (much), more.
M